1. Field of the Invention
This invention relates to punched tape feeding and guiding mechanisms and more particularly to a threading and guiding mechanism to be used in the area of the feed element.
2. Prior Art
The present invention is directed to a mechanism which will provide for automatic, pitch-adapted threading and guiding of a data carrier, such as a punched tape. The mechanism is to be used in the neighborhood of the feed and scanner elements of a perforator punch assembly such as is used to produce the perforations in the punched tape.
Punched tape perforators are known to the art. Many such perforators, particularly those used in association with teletypewriters or teleprinters, are associated with a source of tape, generally an unperforated paper tape wound on a supply wheel. The tape is incrementally drawn, step by step by feed elements through a perforator punch assembly which will perforate the tape in accordance with information supplied to the punch assembly. In order to allow the perforated tape to be read without error, the individual perforations or perforation rows, must be spaced apart at predetermined intervals. That is to say, the "tape pitch" must be properly maintained.
To adjust the tape pitch it has been known to utilize the interval between the punch assembly and a tape driving feed wheel as a control condition. Therefore, for correct guidance of the punched tape, it is necessary to provide punched tape guide tracks on which the tape is guided and which prevent horizontal and vertical displacement and twisting of the tape. When this is accomplished properly, the tape pitch will be maintained constant.
In order to fulfill these requirements, the prior known punched tape guides have been of such designs which, when effective to properly guide the tape, required relatively complicated procedures to thread the unperforated tape prior to perforating operations. In addition, it has been common in prior art designs to require the use of adjusting devices, such as adjusting screws etc., to specifically align and adjust the tape.
Therefore, during both the threading and the adjusting operations, no perforating operations can be carried out. This presents a time delay. It is desired to be able to maintain the threading time as short as possible while utilizing a punched tape guide and threading mechanism which is simple to operate while being effective to maintain proper tape pitch.